Through the late 40's and 50's America's House Committee on Un-American Activities waged a war against communists and communist sympathisers, with special attention paid to the film industry. Through this period a significant number of screenwriters, directors and actors were called to account for their alleged beliefs, ruining lives and careers along the way. In this month's podcast Mark Cosgrove, Watershed Cinema Curator, discusses this dark time in Hollywood and the release this month of the entertaining and illuminating Trumbo – about the Hollywood screenwriter who was blacklisted after refusing to testify to the House Committee on Un-American Activities in 1947.